package com.itheima;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;

public class MapDemo {

    public static void test1(){
        Map<String,Double>map=new HashMap<>();
        map.put("zhangsan",100.0);
        map.put("lisi",200.0);
        map.put("wangwu",300.0);
        map.put("zhaoliu",400.0);
        //将map中的所有键值取出放入set集合
        Set<String> keySet=map.keySet();
        for(String key:keySet){
            //根据key找值
            Double value=map.get(key);
            System.out.println(key+"-----"+value);
        }
    }

    public static void test2(){
        Map<String,Double>map=new HashMap<>();
        map.put("zhangsan",100.0);
        map.put("lisi",200.0);
        map.put("wangwu",300.0);
        map.put("zhaoliu",400.0);
        //1.将map集合转成set集合（将map中的key-value绑定成一个对象entry）
        Set<Map.Entry<String,Double>> entrySet=map.entrySet();
        //2.遍历set集合
        for(Map.Entry<String,Double> entry:entrySet){
            //3.根据entry获取key和value
            String key=entry.getKey();
            Double value=entry.getValue();
            System.out.println(key+"-----"+value);
        }
    }

    public static void test3(){
        Map<String,Double>map=new HashMap<>();
        map.put("zhangsan",100.0);
        map.put("lisi",200.0);
        map.put("wangwu",300.0);
        map.put("zhaoliu",400.0);

//        map.forEach(new BiConsumer<String,Double>(){
//            @Override
//            public void accept(String key,Double value){
//                System.out.println(key+"-----"+value);
//            }
//        });

        map.forEach((key,value)->System.out.println(key+"-----"+value));
    }




    public static void main(String[] args) {
        Map<String,Double>map=new HashMap<>();
        map.put("zhangsan",100.0);
        map.put("lisi",200.0);
        map.put("wangwu",300.0);
        map.put("zhaoliu",400.0);
        map.put("zhaoliu",500.0);

        System.out.println(map);

        map.remove("zhangsan");
        System.out.println(map);
//        map.clear();
//        System.out.println(map);

        boolean b1=map.containsKey("lisi");
        System.out.println("b="+b1);
        boolean b2=map.containsValue(200.0);
        System.out.println("b2="+b2);

        boolean empty=map.isEmpty();
        System.out.println("empty="+empty);
        int size=map.size();
        System.out.println("size="+size);


    }
}
